Where Did The Rule Of 72 Come From?

The Rule of 72 – Why it Works

You can think of this as The Rule of 69 (multiplying the .69 by one hundred, so that the interest rate can be expressed as a percent instead of a decimal).

It isn’t an estimate – it’s the exact answer for doubling your money, assuming that the interest is compounded continuously.

Albert Einstein

How does the 72 rule work?

The Rule of 72 is a simple way to determine how long an investment will take to double given a fixed annual rate of interest. By dividing 72 by the annual rate of return, investors obtain a rough estimate of how many years it will take for the initial investment to duplicate itself.

Where does the Rule of 70 come from?

Deriving the Rule of 70

The rule of 70 is simply a result of the mathematics of compounding. Mathematically, an amount after t periods that grows at rate r per period is equal to the starting amount times the exponential of the growth rate r times the number of periods t. This is shown by the formula above.

What is the 7 year rule for investing?

The rule says that to find the number of years required to double your money at a given interest rate, you just divide the interest rate into 72. For example, if you want to know how long it will take to double your money at eight percent interest, divide 8 into 72 and get 9 years.

Does money double every 7 years?

The Rule of 72 states that the amount of time required to double your money equals 72 divided by your rate of return. For example: If you invest money at a 10 percent return, you will double your money every 7.2 years. If you invest at a 7 percent return, you will double your money every 10.2 years.

What is the rule of 42?

In finance, the rule of 72, the rule of 70 and the rule of 69.3 are methods for estimating an investment’s doubling time. The rule number (e.g., 72) is divided by the interest percentage per period (usually years) to obtain the approximate number of periods required for doubling.

What is Rule of 144?

16, 2013. When you acquire restricted securities or hold control securities, you must find an exemption from the SEC’s registration requirements to sell them in a public marketplace. Rule 144 allows public resale of restricted and control securities if a number of conditions are met.

Why is 72 the best number?

Sheldon: “The best number is 73. 73 is the 21st prime number. Its mirror, 37, is the 12th and its mirror, 21, is the product of multiplying 7 and 3 and in binary 73 is a palindrome, 1001001, which backwards is 1001001.”

Why is Rule 72 important?

The Rule of 72 is a quick, useful formula that is popularly used to estimate the number of years required to double the invested money at a given annual rate of return. Alternatively, it can compute the annual rate of compounded return from an investment given how many years it will take to double the investment.

What is the 70/30 rule?

THE 70/30 RULE OF COMMUNICATION. There is an old rule that is familiar to many but practiced and mastered by only a few of the best sales people. It is called the 70/30 Rule of Communication. That means that the sales person is actually doing more listening during the sales call than anything else.

What is the 70 rule in house flipping?

What is the 70 percent rule? The 70 percent rule states that an investor should pay 70 percent of the ARV of a property minus the repairs needed. The ARV is the after repaired value and is what a home is worth after it is fully repaired.

Is the rule of 70 accurate?

However the Rule of 70 is not always so accurate. According to the Rule of 70, the principal and interest will double the initial principle after 70/100 = 0.7 years. The actual doubling time for an investment returning 100 percent each year is one year.